Cokedkill



Dec. 9, 1-941. 0. M. POTTER EIAL COKE DRILL Filed Sept. 23. 1959 FIGQE FIG. 3

FIG. 4

R nu s R m A .v.. Mum m so 3 M C a Y- H B T mental or. a, 1941 COKE DRILL Charles M. Potter, Glendale, and Alonzo D. Bell,

Taft, Calm, auignors to The Bahrein Petroleum Company Limited, New York, N. Y., a

company of Canada Application September. 23, 1939, Serial No. 296,172

3Clalm8.

This relates to devices for cutting and removing material such as coke from a vertical coke still or drum.

During a coking operation the coke drums of which two or more are generally employed al- I ternately in a pressure coke still unit, become filled with hard brittle coke. This cokels used in the electrical industry and also commercially as fuel and it is preferable that the coke remain in more or less uniform lumps rather than in the powdered or pulverized form.

The principal object of the invention is to pro-v vide a device or tool for rapidly cutting the coke from the coke drum and in such a manner that the coke will not be broken into powder but With this procedure two separate operations are necessary since the center hole must first be drilled completely through the mass and then the bit must be changed and the chain and knocker unit substituted so that the second operation can take place. With this arrangementthe chain and ball unit must be rotated about 200 R. P. M. in order that the centrifugal force will be sufficient to hold the chains out straight. With the present invention on the other hand, the maximum speed of rotation required is only about'35 R. P. M.

The drums are sometimes lined with corrosion resistant metal and the balls swinging on the chains occasionally gouge the walls of the vessel and thereby puncture the lining with attendant damage and loss of time for repairs. Furthermore, in drums more than ten feet in diameter it is almost impossible to break up the coke with the ball and chain method while on the other hand, this invention can be used successfully in large drums. With this invention the drums may be placed at relatively high elevations so that coke can be delivered by gravity from the drums to railroad cars or trucks. c

Other means for removing coke have been tried such as the mounting of a cable or chain in the vessel or drum so that it will become imbedded chain is pulled out the coke is supposed to be broken up so that it can be removed. With this method also, the coke is seldom uniformly broken and the preliminary hanging of the chain or cable is'another time-consuming operation. With hard cokethe chains often break before they can be pulled from the vessel and pieces of the chain are frequently mixed in with the coke.

With the present invention, the coke is removed quickly and in comparatively uniform lumps with a minimum of the coke becoming powdered. Only one operation is necessary since a preliminary hole'does not need to be drilled through the length of the cok mass. No other preliminary operation such as the hanging or positioning of a chain or cable is necessary.

In carrying out the invention after the vessel or drum has been filled with coke and sufflciently cooled, the bottom manhole is removed and the cutting tool is inserted upwardly into the lower portion of the coke mass. The tool com- "prises a pilot or guide pit and a plurality of cutting arms pivoted to a drill head so that they can be folded up vertically to be inserted through the manhole. After the unit has been inserted, it is rotated about a vertical axis and the cutting arms swing outwardly toward a horizontal position due to the force of gravity. After the cutting arms have reached their horizontal position the unit while rotating maybe raised until it comes in contact with the lower surface of the coke mass and teeth arranged on the arms cut and break up the coke into lumps which then pass downwardly through the manhole. The arms are of such length that their outer ends in rotating come close to the vertical walls of the vessel and when the unit'is being raised the ends of the'arms will thus position the device centrally of the drum. The rotation of the unit will jar the vessel slightly and the coke mass will slide downwardly into contact with the rotating cutting arms so that it will be broken into lumps. Since the coke is contacted by the cutting elements in the lower portion of the drum the coke lumps do notfall any appreciable distance through the drum and they are therefore not completely broken up and pulverized as has lower portion of a coke drum showing the coke mass which has moved downwardly into contact in the coke. When the drum is opened and the with the cutting unit;

as tungsten carbide.

Figure 2 is a diagrammatic vertical elevation showing the cutting operation just after the arms have begun to spread out to assume their normal horizontal position;

Figure 3 is a vertical elevation of'the cutting unit with the arms raised for insertion into the vessel:

Figure 4 is a partial'secticnal through the drill head,and v i Figure 5 is a plan of the cutting unit with the outer portions of the arms broken away.

Referring to the drawing, a coke drum or vessel I0, is shown as having a mass of coke I2 therein, the lower wall of the drum being provided with a manhole 14. A rotatable and vertically movable shaft l6 which may be the kelly desired, be disposed on the various arms 34 in staggered relation to each other. When the arms 34 are in their horizontal position their verticalelevation As will be observed with reference to Figure 1,-

there is an appreciable distance between the pilot bit 28 and the innermost of the teeth 36 on the arms 34 and in order to cut the coke from the mass in this space a plurality ,of cutting elements bar, of a drilling unit isarranged so that it can,

while being rotated, be pushed upwardly into the coke mass. A drill head l8 shown more clearly in Figures 4 and 5 is secured to the upper end of the shaft I6. This head comprises atubular member 20 1 presently. A pilot or guide bit 28 is suitably secured to the upper end of the tubular member 20. This guide bit may be of any suitable type but is shown as being formed of two intersecting plates pointed at their tops and mounted centrally in a supporting member 30. The sides of the member 30 are bent or curved inwardly,

as shown in Figure 4, to engage the intersecting plates and the parts may be suitably welded to form a solid unit.

A pair of bolts 32 pass at right angles to each other through the brackets 26 and the tubular member 20. Pivotally supported on these bolts are four arms 34, in such a manner that when it is desired to insert the unit into the vessel the arms can be folded or tuned upwardly as is shown in Figure 3, after which they will tend. to spread out so as to assume the horizontal position in which they are shown in Figure 1. Each arm 34 is slightly tapered from end to end and the hole through which the bolt- 32 passes is disposed slightly at one side 'of the axis of the arm. Because of this eccentric mounting the arms when in a vertical position will always be biased from that position. and there is no danger that the arms would remain vertical after the rotation has commenced. -Another purpose of pivoting the arms at one side is to provide for additional clearance when the of coke which might collect in the spaces between the bracket 26 and the tubular member 20 will have less tendency to, obstruct the movement of the arms 34 when they are moving'upwardly toward the vertical position.

A shown in Figure 1, each arm 34 is provided along its upper edge. with a plurality of teeth 33, the cutting edges or ends of which may be surfaced with some hard facing material such Each arm 34 is also provided along its lower edge with a plurality of shorter teeth 38. The teeth 36 and 38 may, if

or blades 40 are provided. These cutting members 40 are welded or otherwise affixed to the upper ends of the brackets 26 and project upwardly. Upon rotation of the unit, these elements 4!] will cut away that portion of the coke mass which would not be engaged by the bit 28 or the teeth 36. This is an important feature since otherwise the ring of coke which might remain uncut would clog up or otherwise damage the pivotal connections between the arms 34 and the drill head l8. As shown in Figure 4, a bolt 42 is preferably passed'through the joint formed by the tapered members 22 and 24 so as to hold the drill head on the shaft l6 more firmly. A plurality of projecting members or lugs 44 are secured to the tubular member 20 of the drill head in such a manner that they serve as stops for the arms 34. The arms in their horizontal position rest upon these stops and are thus prevented from swinging downwardly past the horizontal position.

It is believed the operation will be clear from the foregoing description. However, to summarize, the drill head and the cutting arm which have been previously made up, as shown in Figur 3, are forced upwardly through the manhole l4 and the shaft I6 is rotated at the same time. The upper ends of the arms 34 and the teeth 38 will drill a center hole up into the coke mass l2 and after the unit has been forced up into the vessel to a position such as is shown in Figure 2, the arms 34, being biased away from their vertical position because of their eccentric mounting on the drill head l8, will swing outwardly, as shown in Figure 2, and in so doing the lower teeth 38 will cut away the coke from the lower portion of the vessel. The arms 34 will soon reach their horizontal position, as

' shown in Figure 1, and will b maintained in that position by the stops 44. The unit while rotating may then be forced upwardly until the upper teeth 36 contact the coke mass which will be broken up into lumps by these teeth.

The slightjarring of the vessel caused by the rotation of the drill unit and the friction between i the rotating arms and the coke causes the coke mass to become loosened from the vertical walls of the vessel so that the mass will then slide downwardly gradually into contact with the teeth 36 of the cutting arms. This downward sliding of the coke mass is also further assured by the desired location. It has been found that in almost all cases the coke mass loosens and slides downwardly in the vessel as has been described.

However, in the event that the coke does not loosen from the walls of the vessel, it is merely necessary to force the shaft I6 and the cutting unit upwardly while continuing the rotation until all of the coke has been broken up and removed. The pilot bit 28 precedes the cutting arms and serves to guide the cutting unit. The outer ends or tips of the cutting arms may from time to time rub upon the inner walls of the vessel and in so doing will maintain the unit centered in the coke mass. Because of this fact, the shaft l6 need not be as heavy and large as would be the case if this guiding or centering action were not present. As has been stated hereinb'efore, the blades 40 will cut away the coke between the pilot bit and the innermost teeth 36.

After all of the coke has been broken up and removed from the vessel, rotation is stopped and the unit is pulleddownwardly. The arms 34 can be moved angularly upwardly so that they can pass through and out of the manhole It.

It is customary to have two or three coke drums in operation at the same time, and the coke will be drilled from one of the drums while the coking operation is taking place in the others. In this manner the operation is substantially continuous, and because of the increased speed with which the coke is broken and removed, it has been found that the capacity of coking units can be doubled through the use of this apparatus. In an installation embodying this invention and which is now in operation, it has been found that frequently a truck can be filled with the lumps of coke in less than 1 minute.

Obviously many modifications and variations of the invention as above set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated by the apand a substantially horizontal position, cutting teeth on the lower sides of said arms to cut the coke while the arms are swinging from the vertical to the horizontal position, and a plurality of cutting members mounted on said head and disposed between said pilot bit and the teeth on said arms.

2. In a device for drilling coke from a vessel provided with an opening in its bottom, a shaft rotatable about a vertical axis, a drill head, a tapered connection between said drill head and the upper end of said shaft, a centering guide bit secured to and projecting upwardly from said drill head, a plurality of cutting arms pivotally secured to said drill head and adapted to be swung upwardly to a position parallel to said shaft so that the device can be inserted into and withdrawn .from the vessel through said opening, the pivotal connection of said arms being disposed slightly to one side of the center line of the arms so that the arms when in their vertical 1 position will be biased to swing toward a horizontal position, and teeth on said arms adapted to engage and cut the coke when said arms are rotated.

3. In an apparatus for breaking up a mass of coke in a coke drum, a vertically disposed rotatable shaft, a drilling unit secured to the upper end of said shaft, said unit comprising a body member having a'tapered connection with the upper end of said shaft, a pointed guide bit secured to and projecting upwardly from the top of said body member, brackets each secured at one end to said body member, a cutting blade rigidly secured to and projecting upwardly fromeach of said brackets, bolts passing through oppositely disposed brackets and said body member, a plurality of arms each being pivoted at one end on one of said bolts between a bracket and said body member and adapted to be swung between vertical and horizontal positions, said arms being sufflciently long to extend fromsaid pivotal connection substantially to the inner surface of the vertical walls of said coke drum so as to center the shaft within the drum, and teeth on the upper and lower sides of said arms adapted on rotation of said drill unit to engage and cut the coke mass. 1

CHARLES M. PO'I'IER. ALONZO D. BELL. 

